Electrical relay



Aug. 18, 1931. A. J. SORENSEN L ELECTRICAL RELAY Filed May 9, 1930INVENTOR [LJTSorenSen 67 Q3.

Patented Aug. 18, 1931 UNITED STATES ,PATENT- OFFICE ANDREW J. SORENSEN,OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNALCOMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIAELECTRICAL RELAY Application filed May 9, 1930. Serial No. 451,028.

My invention relates to electrical relays, and has for an object theprovision of means for preventing the condensation of moisture on arelay contact during a change in the 6 ambient temperature.

I will describe one form of relay embodying my invention, and will thenpoint out the novel features thereof in claim.

In the accompanying drawings, Fig. 1 is 10 a view showing in sideelevation, a portion of a relay embodying my invention. Fig. 2 is an endView of the parts shown in Fig. 1.

Similar reference characters refer to similar parts in each of theviews.

Referring to the drawings, the reference character 1 designates the topplate of an electrical relay of the type commonly used in railwaysignaling. Passing through the plate 1 is a terminal post 4, whichcarries a fixed contact member 2 the free end of which is provided witha contact tip 2 for coaction with the movable member of the contact. Themovable member and the other parts of the relay are not shown in thedrawings, because they form no part of my present invention. It issufficient to say that in accordance with standard practice, the contactmember 2 is located in an enclosure of which the plate 1 forms the top.As here shown, the contact member 2 is in the form of a strip of metal,although this specific type of contact member is not essential to myinvention.

Attached to the member 2 is a mass of metal 3, the purpose of which isto cause the temperature of the member 2 to lag behind that so that thecontact member will be kept at a substantially higher temperature thanother parts of the relay, such for example, as the top plate 1. Itfollows that any moisture in the relay will tend to be precipitated onsuch other parts rather than on the contact member 2 and its contact tip2 Consequently, when the temperature drops below the freezing point,there will be less danger of the contact freezing in its closedposit-ion when the member is equipped with the metallic mass 3 than whenit is not equipped with such mass.

Since the path through which the heat must escape should be made as longas possible, the metallic mass 3 should be placed as close as possibleto the contact tip 2*.

Although I have herein shown and described only one form of relaycontact embodying my invention, it is understood that various changesand modifications may be made therein within the scope of the appendedclaim without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

In an electrical relay, a metallic contact member, and a mass of metalattached to said member to cause the temperature of the member to lagbehind that of other parts of the relay during a drop in the ambienttemperature.

In testimony whereof I affix my signature.

ANDREW J. SORENSEN.

from the contact member 2 through the termi- 40 nal post 4 and the usualwires attached to this post. The rapidity with which the temperature ofthe contact member will decrease under this condition, will depend,among other things, upon how much heat has to be conducted out by theterminal post. For a given temperature difference between the inside andthe outside of the relay, the temperature of the contact member 2 whenequipped with the metallic mass 3 will decrease more slowly than withoutthis mass,

